I would join a Tennis club if I were you. The costs associated with it are much cheaper and it sounds like it is more in line with your activities. Most of them these days offer things like a Pool, Gym, etc and some have nice clubhouses with restaurants.
I'm a member at a local Tennis club and I love it, it's a great way to meet new friends who have the same interests as you do and I find that club members tend to be the ones who are really dedicated to the sport. Some people use it for business contacts as well but I'm just more interested in playing.
Interesting to see that this thread is still going. I actually have an interview for membership next week. Then the board will vote whether to let me in or not within a week or so. I am only going for the social membership...access to everything but golf. It wasn't worth it for me at this time since I don't play enough to take advantage of it. And the difference in initiation and monthly dues is very substantial. Plus I can convert the membership at any point in time in the future and the initiation fee that I pay is applied. Ultimately the decision to join came down to: -Providing a fun and safe environment for our son (who's due in Oct) to grow up in -Networking opportunities -Pool access for my wife
So what, is there another country club besides the one in Brookline MA? How curious.
Before you make any decision you should consider that if it comes down to one or the other, sending your child to a private school would be much better than joining a club. $40K/year now grade 7 or 9 through 12, then the cost of a good feeder school, which needs a good feeder preschool etc.